Being consistently active on four different forums, I have enjoyed all the benefits mentioned above one time or another. However, the last benefit – marketing yourself, must be done discreetly. In other words, if one is to market themselves in a forum which is comprised of an active community, marketing one’s self should be subtle. In reality the only true way to market yourself effectively is not to market yourself at all but rather to contribute quality to the forum. When you do that, you market yourself naturally.
From Threadwatch, the New Jersey state legislature is considering a bill that would disallow anonymous speech on forums. While this only relates to New Jersey law, the proposed bill is pretty bold in its attempts and could set a precedent for other states or even national law if passed.